ALGOL (ALGOrithmic Language)

ALGOL is a family of high-level programming languages originally developed in the late 1950s. ALGOL is a mathematical language [1], indeed the name comes from ALGOrithmic Language [2]. The language has had a major influence on modern languages like C and Pascal and their derivatives which have gone on to dominate the world. Modern languages like these are sometimes referred to as "Algol-like".

ALGOL was originally created at a committee of American and European computer scientists in 1958. It was developed to try and rectify what were saw as problems with other early languages such as FORTRAN. ALGOL has been a major research and teaching language and became the standard for the publication of algorithms. This ensured its influence on future language development.

There have been three standards of ALGOL, the first was ALGOL 58 as originally defined. It was followed by ALGOL 60 and finally ALGOL 68 which added new elements to the language. However, ALGOL 60 remained the most popular version as some thought the ALGOL 68 changes went a bit too far and could be considered a whole new language.

As well as usage in academia and research examples of ALGOL usage includes the software on the Soviet Buran space shuttle, computer systems of the Royal Air Force in the Cold War and a number of operating systems from companies like ICL and Burroughs. It is still used on Unisys mainframes as a system language and elsewhere on "legacy" systems (including some UK government departments).

Finally lets look at some code examples of ALGOL 60. Even if you are unfamiliar with the language and never seen it before if you know a bit of C, Pascal or similar then ALGOL is perfectly understandable:

for n:= 5 step 1 until 10 do
begin x:=n/5
end;

if fract(p) > 0.5 then a := p;

day := day + days[month];

One thing ALGOL 60 did lack was input and output facilities. This was left to individual implementations of the language and thus differed between computer manufacturers.

[1] Eric Foxley & Henry R. Neave, A First Course in ALGOL 60 (Addison-Wesley, 1968) p. 5
[2] Graham C. Lester, Data Processing Vol 1: Hardware & Programming (Polytech, 1980) p. 203

COMAL (Common Algorithmic Language)

COMAL was a programming language first developed in Denmark in 1973 by Borge R. Christensen and Benedict Lofstedt [1]. The language was a structured language and heavily influenced by contemporary popular educational languages including BASIC and Pascal, indeed the intention of the developers of COMAL was to try and combine the simplicity of BASIC with the power of Pascal [2].

What made COMAL stand out was that it was available for 8-bit microcomputers in the late 1970s and early 1980s and was one of the few structured languages available for those computers at the time. Though like a number of "alternative" languages (like Forth on the Jupiter Ace) BASIC proved impossible to dislodge as the language "everyone" had.

COMAL did have some success though and is still used to this day as a teaching language, it was especially popular in Ireland in the 1980s where Apple supplied around five hundred Apple IIs running COMAL-80 to schools. Earlier versions of COMAL had no graphics commands but these were added later on especially to Commodore implementations of the language which included turtle graphics.

Now for some examples of COMAL, if you are familiar with languages like BASIC then COMAL will seem very familiar:

0010 PRINT "HELLO WORLD"

0010 INPUT AMOUNT
0020 PRINT "PLEASE PAY ", AMOUNT

0010 PRINT "HOW MANY TIMES?"
0020 INPUT TIMES
0030 FOR NO:=1 TO TIMES DO
0040  PRINT "HELLO NUMBER ", NO
0050 NEXT NO

[1] John Kelly, Foundations in Computer Studies with COMAL (2nd Edition) (Educational Company of Ireland, 1984) p. vii
[2] Borge R. Christensen, Beginning COMAL (Ellis Horwood, 1982) p. 6

SNOBOL (StriNg Oriented and symBOlic Language)

At first glance SNOBOL does seem like a typo of a more familiar sounding programming languages like COBOL but in fact SNOBOL is a series of languages developed at Bell Laboratories by David J. Farber, Ralph E. Griswold and Ivan P. Polonsky in the early 1960s. SNOBOL was designed for text processing and pattern matching and was quite different to most other programming languages of the time.

SNOBOL was originally developed for the symbolic manipulation of polynomials on the IBM 7090 mainframe in 1962. The language became popular and was refined and expanded culminating in SNOBOL4 in 1967.

SNOBOL4 was based on a virtual machine which meant it was much more portable. The language was popular in teaching, artificial intelligence and text manipulation in the 1970s and 1980s though it has been eclipsed by newer tools and languages in the last few decades.

More recently derived languages like SL5 and Icon have added structured language concepts to SNOBOL (which has none itself).

So how do you do a "Hello World" program in SNOBOL?

OUTPUT = "Hello world" 
END